Brainy and bespectacled rat Ethelyn, an aspiring brain surgeon, earns the respect of her fellow ``ratlettes'' in a fast-paced tale especially helpful to those adjusting to a new school. When Ethelyn arrives at Cheddar Gables College, she is ostracized by the other students and dejectedly retires to her ``dormousery'' for the night. Things go from bad to worse: first, she is frightened by a ghost (albeit one propelled by suspiciously rodent-like feet) and later, she is unjustly accused of stealing the principal's cheese. Just as Ethelyn implores her brother to rescue her, she is granted the opportunity to confront the ghost, solve the mystery of the stolen cheese, use her medical know-how and win over her heretofore inimicable peers. Cole's ( Cupid ; The Silly Book ) spindly-legged, goggle-eyed creatures are silly and likably gawky; and speedy--if somewhat jarring--turns of plot command attention. Ages 4-8. (Sept.)